Stud cartridge shell



9 H. GAWLICK ETAL 3,120,808

STUD CARTRIDGE SHELL Filed April 19, 1961 a I v2 IIIIIIIIIIIII/lfllllll/ F J. EA I INVENTORS ATTORNEYS United States Patent 3,120,808 STUD CARTRIDGE SHELL Heinz Gawliek, Furtli, Bavaria, and Hans K. L. Stadler, Nurnherg, Germany, assignors to Dynamit Nobel Aktiengesellschaft, Troisdorf, Germany, a German corporation Filed Apr. 19, 1961, Ser- No. 104,081 Claims priority, application Germany May 9, 1960 8 Claims. (Cl. 102-44) The present invention relates to a stud cartridge shell usable for rim firing in a stud gun having a firing chamber which opens relatively slowly in response to the firing, and more particularly to such a shell having a bottom wall of greater thickness than the remainder of the shell.

In order to produce industrially applicable energy by the detonation of propelling powder charges, such charges are detonated in a closed firing chamber in a convenient manner. In a weapon in which a projectile is propelled through the barrel by means of a powder charge, the breech block at the rear end of the cartridge remains rigidly closed during the firing and opens only at a specific point, in order to actuate an automatic reload, etc. in a convenient manner. In stud gun devices for the industrial utilization of the powder energy, the muzzle end of the stud gun is sealed off. In order to allow the energy of the expanding powder gases to come to efiect, it is necessary to provide the breech block which covers the rear end of the firing chamber as a displaceable member rather than as a rigidly closed member. Generally, the breech block is arranged for movement into and out of closing contact with the rear end of the firing chamber. The breech block may be of the blow-back variety which is impelled rearwardly by the force of firing, immediately upon firing or the same may be of the recoil type wherein the breech block is moved rearwardly after a certain degree of recoil has been achieved which may overcome a spring force normally urging the breech block into closed position against the rear end of the firing chamber. Industrial stud guns find wide application in forcing nails and the like into objects against which the gun is placed for firing. In the usual commercial stud gun, the powder charge is provided in metal cartridges equipped for central firing or rim firing. For

reasons of economy, rim firing cartridges are preferred.

Since the powder gases which form as a result of the cartridge firing are contained in a firing chamber or cartridge chamber having a volume which practically equals the volume of the cartridge itself, the pressures generated within the interior of the firing chamber or combustion chamber are considerable and even exceed by far the pressure values generated by the usual rifle cartridges. The powder gases generated upon firing the cartridge in a stud gun must work against the difiiculty opening breech block which acts as a piston in some respects. Because of the considerable pressures generated upon firing cartridges in stud guns, the cartridge shell can only poorly stand up under the stresses and strains. This is particularly true if the cartridge is provided with rim ignition means.

Understand-ably, in the interests of economical and "efficient servicing of the industrial stud gun device, it is necessary that no remnants of a previously fired cartridge will remain in the firing chamber so that a quick reloading for further firing may be achieved. It has been found, however, that the usual cartridges employed, for

example, in nail-driving stud guns are unsuitable since they are torn into many small metal fragments. During the release of the generated pressure upon firing, the metal jacket is torn open at least a several points, whereby fragments remaining in the firing chamber render difiicult the quick reloading and reuse of the stud gun. Since it is not technically feasible to provide a different manner of pressure release in the firing chamber, attempts have been made to reduce the number of fragments of the cartridge shell which occur upon firing to at most two. Obviously, two comparatively large fragments of a used cartridge will readily drop out of the firing chamber such that the working parts of the stud gun will not jam due to the undesired presence of small cartridge fragments on the working surfaces of the device.

Specifically, a stud gun device is known comprising a stand frame which may be set against the surface into which the nail is to be driven, such stand frame containing an upper piston of heavy mass analogous to the closed or muzzle end of a gun as well as a lower piston of lighter mass arranged for movement within the stand frame from a position in abutment with the bottom end of the upper piston to a position out of abutment therewith and axially displaced with respect thereto. A cartridge chamber or firing chamber is defined in the lower surface of the upper piston such that the cartridge is inserted therewithin with the cartridge bottom wall facing the upper surface of the lower piston. The lower piston is suitably provided with a rim firing pin, such that when the upper piston is caused to move downwardly against the lower piston, the impact will cause the firing pin to detonate the cartridge. The gases generated upon firing will work against the upper surface of the lower piston causing the downward displacement thereof. By conveniently placing a nail at the underside of the lower piston, such nail may be effectively driven into the surface against which the stand frame is placed, in the desired manner. The upper piston may be considered a member closing ofi the muzzle end of the device while the lower piston may be considered the breech block of the device which simultaneously serves as the impelling member for eiiectuating the driving pin of a nail, bolt, etc. into the adjacent surface in the desired manner.

It is an object of the present invention to overcome the foregoing drawbacks and to provide a stud cartridge shell usable for rim firing in a stud gun having a firing chamber which opens relatively slowly in response to the firing, such stud cartridge shell comprising a cylindrical casing having a bottom wall connected thereto of greater thickness than the casing.

Other and further objects of the invention will become apparent from a study of the within specification and accompanying drawings in which:

FIGURE 1 is a schematic partial sectional view of the lower end of a stud cartridge shell in accordance with one embodiment of the invention,

FIGURE 2 is a schematic partial sectional view of a stud cartridge shell in accordance with another embodiment of the invention,

FIGURE 3 is a schematic partial sectional view of a stud cartridge shell in accordance with a further embodiment of the invention, and

FIGURE 4 is a schematic sectional view of a stud gun device positioned in relation to the surface into which the stud or nail is to be driven, illustrating the manner in which the cartridge shell of the invention is used.

It has been found in accordance with the present invention that a stud cartridge shell of improved construction usable for rim firing in a stud gun having a firing chamber which opens relatively slowly in response to firing may be provided, the cartridge shell comprising a cylindrical casing having a bottom wall connected thereon, the bottom wall for said casing having a pronouncedly greater thickness than the casing. Significantly, a clear delineation is defined between the respective thickness of the casing and the bottom wall of the cartridge shell at the connection therebetween.

Preferably, the ratio of the thicknesses of the bottom wall and the casing is within the range of from about 2:1 to 10:1. f

In accordance with one embodiment of the invention, the casing is provided with a bottom end portion which frusto-conically outwardly extends to the bottom wall, such bottom end portion being optionally integrally connected with the bottom wall. The bottom end portion may have the same thickness as the casing and thus be connected with the bottom wall at the outermost portion of the bottom end portion. Alternatively, in accordance with another embodiment of the invention, the bottom end portion may have the same thickness as the bottom wall, whereby the same defines an inwardly directed shoulder adjacent the innermost portion thereof, at the connection between the thicker bottom wall and. the thinner casing thereat. In accordance with a still further embodiment of the invention, the casing may be provided with the bottom end portion which annularly extends outwardly and then inward-1y from the casing to the bottom Wall. In this instance, the bottom wall is provided with a reinforcement cap extending thereover.

The reinforcement cap has an annular flange inwardly directed over and clampingly engaging the outer surface of the bottom end portion. Suitably, the bottom end portion defines an outwardly directed lip arcuate in cross section and the annular flange defines a correspondingly shaped outwardly enclosed groove for securingly receiving the lip therewithin. In the last-mentioned embodiment, the bottom wall has the same thickness as the casing and the bottom end portion, while the reinforcement cap is at least as thick as the bottom wall or preferably thicker than the bottom wall.

By providing the stud cartridge shell with a casing and a bottom wall of markedly different wall thicknesses a well-defined, rapid separation of the thick bottom wall from the remaining thin casing will take place upon firing in the cartridge chamber of the stud gun. Accordingly, no further fragmentation of the cartridge shell will occur, permitting easy removal of the two large fragments for quick reloading and reuse of the stud gun. A welldefined delineation is present between the ditferent thickness wall portions, so that upon firing, the bottom wall will be cleanly separated from the casing poistioned within the firing chamber. The thicker bottom wall as opposed to the thinner casing may be produced by special stamping tools or cutting tools. However, it is also possible to provide a thicker bottom wall by reinforcing a bottom wall having approximately the same thickness as the casing by means of an overlying cap.

Referring to PHGUR'E l, a blank separating stud firing cartridge shell is shown having a generally tubular or cylindrical casing shank 1 and a base or bottom wall 2 which is about 3 times as thick as the casing shank 1. A frusto-conical bottom annular end extension 1 is provided of the same thickness as the casing shank 1 for interconnecting the casing shank 1 with the radially outward edge of the thicker bottom wall 2. A conventional primer composition 5 is provided so as to form a rim firing primer with the adjacent base structure while a propellant 6 is -located in the usual way in casing shank 1 for generating high pressures upon rim firing of the cartridge.

With respect to FIGURE 2, the casing shank 1 is connected with the bottom wall 2, which is about 3 times as thick as the casing shank 1, by means of the frusto-conical bottom annular end extension 2' having the same thickness as the bottom wall 2. In this instance, the radially inner edge of extension 2' forms the shoulder or separation groove 3, the outer portion of extension 2' being connected with the casing shank 1. A primer composition and propellant are provided (not shown) in the same manner as in =FIG. l for effecting the desired result upon firing.

With respect to FIGURE 3, the casing shank 1 is connected to the bottom wall 2a, having the same thickness thereas, by means of the arcuate bottom annular end extension 2a'. While extension 2a has the same thickness as bottom wall 2a and casing shank 1, the reinforcement cap 4 is disposed over the bottom wall 2a. The arcuate iriwardly directed flange 4' of reinforcement cap 4 clampingly secures arcuate extension 2a. Since reinforcement cap is about 2 to 3 times as thick as the remaining por tions of the cartridge shell, 21 well-defined difference in wall thickness is provided. Similarly to the embodiments of FIGURES l and 2, a primer composition and propelilant (not shown) are provided for effecting the desired result upon firing.

Thus, in each of the embodiments shown in FIGURES 1-3, a well defined separation groove is present so that upon firing, the bottom wall of the cartridge shell will cleanly separate from the remaining casing shank, so that only two shell fragments will occur. Since the bottom wal'l is of thicker dimensions with respect to the easing shank, the bottom wall will stand up under the heavy pressures generated upon firing the cartridge and will be cleanly severed before the pressures of the gases will attack the casing shank 1 to rupture or tear apart the same.

In FIGURE 4, an impelling device or stud gun of the type with which the stud cartridge shells of the present invention may be used is shown. The device includes a stand frame 16 having a bottom flange portion 11 forming a fiat support on its under surface for engaging the adjacent surface of the article 13 into which the stud or nail 22 is to be driven. Stand frame 11 is provided with a central bore 12 into the upper portion of which is slidably received the upper piston 14; having the impact surface .15 at its upper end and the cartridge chamber or firing chamber 15 at its lower end. The cartridge 17 having the thicker bottom wall 18 in accordance with the invention is disposed in the chamber 16, such that the bottom wall 18 faces the upper surface of lower piston 19, positioned within bore 12 at the level of the flange 11. Lower piston '19 is provided with a rim firing pin 20 on the upper surface thereof in 'line with the rim of bottom wall 18 of cartridge 17 and a recess 21 for receiving the upper end of bolt or nail '22. Upon striking the impact surface 15 in the direction of the arrow, as for example by means of a hammer or other suitable implement, the bottom wall 18 of the cartridge 17 will be caused to strike the firing pin 20. Upon firing in this manner, the gas generated within cartridge chamber 16 i.e. by ignition of the propellant in the cartridge will cause bottom wall 18 to be cleanly separated from the remainder of the cartridge 17, at the same time impelling lower piston 19 and in turn bolt or nail 22 into the surface of the article 13 to be bolted or nailed. Of course, bore 12 is suitably dimensioned for slidable displacement of upper piston 14 and lower piston 19 therewithin. The stud driving device of FIGURE 4 is a single load device which may be readily reloaded by removing upper piston '14, for example, replacing the spent cartridge with a new one, and reinserting upper piston 14 into position for firing. In this connection, a new bolt or nail may be placed within recess 21 of lower piston 19 for driving.

It is seen that the particular device shown is one in which the cartridge causes the working pressure to be directed toward the rear of the stud gun, in the manner of the working against the breech block of a gun. No forward pressures are realized, due to the large mass of the upper piston 14 as compared with the small mass of the lower piston '19.

What is claimed is:

l. A blank separating stud firing cartridge, said cartridrge having a generally tubular casing containing a propellant therein, and a base aifixed at one end thereof, said base having a larger external diameter than said casing, said larger diameter forming a rim on said cartridge,

said base having an internal dimension larger than the internal diameter of said casing, the base structure defined by said internal dimension of said base containing a primer composition, said base structure and said primer composition forming a rim firing primer, the cross-sectional thickness of said base being substantially greater than said casing wall thickness, the difference in thickness being set forth in a clear line of delineation between said base and said casing, and said difierence in wall thickness and said clear line of delineation being sufiicient for rupture at the delineation line when said cartridge is fired by said rim primer, said base upon release by rupture from said casing acting upon a stud means to drive said stud means by high pressures generated by the propellant in said cartridge.

2. Cartridge according to claim 1 wherein the ratio of the thicknesses of said base and said casing Wall is between about 2-1011.

3. Cartridge according to claim 2 wherein said casing is generally cylindrical and a bottom annular end portion is provided which -frusto-conically outwardly extends to said base and interconnects said casing to said base.

4. Cartridge according to claim 3 wherein said casing, said bottom annular end portion and said base are integraltly connected.

5. Cartridge according to claim 3 wherein said bottom annular end portion has the same wall thickness as said casing wall and is connected with said base at the outermost portion of said bottom annular end portion.

6. Cartridge according to claim 3 wherein said bottom annular end portion has the same wall thickness as said base, and defines an inwardly directed shoulder adjacent the innermost portion of its cross-section at the connection between the base and the casing wall thereat.

7. Cartridge according to claim 2 wherein said base includes a bottom end wall portion connected to said casing and a reinforcing cap extending externally over said bottom end wall portion, said cap having an annular flange inwardly directed over and clampingly engaging the rim formed by the larger external diameter of the base at the bottom end wall portion thereof.

8. Cartridge according to claim 7 wherein said casing wall and said bottom end Wall portion have substantially the same thickness and said reinforcement cap is at least as thick as said bottom end wall portion, whereby said bottom end wall portion and said cap together define a base of greater thickness than said casing.

References Cited in the file of this patent UNITED STATES PATENTS 1,002,038 Clyne Aug. 29, 1911 1,461,013 Hodge July 3, 1923 2,262,925 Cole Nov. 18, 1941 2,522,208 Catlin Sept. 12, 1950 FOREIGN PATENTS 1,081,535 France June 9, 1954 1,082,067 France June 16, 1954 

1. A BLANK SEPARATING STUD FIRING CARTRIDGE, SAID CARTRIDGE HAVING A GENERALLY TUBULAR CASING CONTAINING A PROPELLANT THEREIN, AND A BASE AFFIXED AT ONE END THEREOF, SAID BASE HAVING A LARGER EXTERNAL DIAMETER THAN SAID CASING, SAID LARGER DIAMETER FORMING A RIM ON SAID CARTRIDGE, SAID BASE HAVING AN INTERNAL DIMENSION LARGER THAN THE INTERNAL DIAMETER OF SAID CASING, THE BASE STRUCTURE DEFINED BY SAID INTERNAL DIMENSION OF SAID BASE CONTAINING A PRIMER COMPOSITION, SAID BASE STRUCTURE AND SAID PRIMER COMPOSITON FORMING A RIM FIRING PRIMER, THE CROSS-SECTIONAL THICKNESS OF SAID BASE BEING SUBSTANTIALLY GREATER THAN SAID CASING WALL THICKNESS, THE DIFFERENCE IN THICKNESS BEING SET FORTH IN A CLEAR LINE OF DELINEATION BETWEEN SAID BASE AND SAID CASING, AND SAID DIFFERENCE IN WALL THICKNESS AND SAID CLEAR LINE OF DELINEATION BEING SUFFICIENT FOR RUPTURE AT THE DELINEATION LINE WHEN SAID CARTRIDGE IS FIRED BY SAID RIM PRIMER, SAID BASE UPON RELEASE BY RUPTURE FROM SAID CASING ACTING UPON A STUD MEANS TO DRIVE SAID STUD MEANS BY HIGH PRESSURES GENERATED BY THE PROPELLANT IN SAID CARTRIDGE. 